I've been doing some research on this matter and would appreciate any input you have.

We're looking at moving a page of our website to a sub-domain and having a main keyword as the sub-domain in the aim to rank higher for said keyword.

I personally don't think this will help by moving just the one page, if it does it must be extremely minimal and time would be better spent improving the actual content and user experience. I think earning links to our main domain will benefit both the domain and also the page that's being considered to be moved.

Do you think having keyword.domain.com would have any value in regards to SEO?

Keyword-rich URLs have relatively little impact on search results unless people link to those destinations with the URLs as the anchors. Unless you're expecting a lot of people to link to the proposed subdomain it won't help, unless the main site has been downgraded by Panda (in which case you would NOT want to redirect the old URL to the subdomain).

Subdomains should only be developed when they provide a distinctive advantage for user valuation. For example, if you sell handbags, shoes, dresses, and shirts you could hypothetically create distinctive subdomains that showcase your products in ways that complement that kind of shopping experience. That's an artificial example because it's hard to suggest a way to use subdomains without people thinking, "Aha! We'll just load up our site with keyword-rich subdomains and ...."

Subdomains should be treated as standalone Websites, insofar as they should create real distinctive value. You can integrate them into your comprehensive site navigation but the subdomain should be there for a reason other than "we did it for SEO".

Keyword-rich URLs have relatively little impact on search results unless people link to those destinations with the URLs as the anchors. Unless you're expecting a lot of people to link to the proposed subdomain it won't help, unless the main site has been downgraded by Panda (in which case you would NOT want to redirect the old URL to the subdomain).

Subdomains should only be developed when they provide a distinctive advantage for user valuation. For example, if you sell handbags, shoes, dresses, and shirts you could hypothetically create distinctive subdomains that showcase your products in ways that complement that kind of shopping experience. That's an artificial example because it's hard to suggest a way to use subdomains without people thinking, "Aha! We'll just load up our site with keyword-rich subdomains and ...."

Subdomains should be treated as standalone Websites, insofar as they should create real distinctive value. You can integrate them into your comprehensive site navigation but the subdomain should be there for a reason other than "we did it for SEO".